Take a look at page 3 of your ebill. The $15 charge is more likely a charge for your prorated plan or maybe a overage charge in your minutes.
If you dont understand what the charge is still, take a screenshot of your ebill excluding any personal info and post it here and we can explain it to you.

The above is the data usage that indicates a $11.27 fee.. I don't use data when not connected to the internet.. Now the other day I down loaded a app but I was connected to the internet and I have 100mb in my plan.

The usage distribution is strange:14 instances of 0.25 MB @ $0.751 instance of 0.12 MB @ $0.001 instance of 10 MB @ $0.50 > this is the in Canada Pay per use data rate1 instance of 5.31 MB @ $0.27 > this is the in Canada Pay per use data rate

There is obviously some data leakage from your phone. Do you know what apps are using data? You can check this out in Settings>Data UsageYou can then turn off data for these apps or remove them. However other apps may use data unknowingly in the future.

You can also get the Data block with Picture messaging add-on. It is the surest way﻿

Cellphones can be tricky. Sometimes they use data even when we dont want to. It has happened to me in the past as well and I know it can give a feeling of helplessness since you are not entirely in control.

If you do not actively send pictures, then I would advise that you turn off your data to prevent this from happening again.

It still should not have charged you if you had 100MB included at the time and wasn't roaming. You can send a private message to Koodo via Facebook or DM via Twitter to have them look at it and get it reversed if it wasn't roaming or an overage is confirmed.

The android OS sometimes has minimal use, like say if weather notification is built in and the like. Do you have data fully shut off?

I have my data shut off Goran however if I keep it off I cant open a picture text message. I also have the overage in data alert turned off and I didn't receive a notification I was going over my 100mb. when I look at my bill it has 30.43 Mb for a total however on there is a 15.00 charge on a specific date showing usage of 19.02mb?

The current 30 dollar 100MB plan will automatically shut off data usage once you hit 100% if you have notifications turned on, and will only allow more data usage if you reply to the text message that gets sent to accept additional data charges. I would definitely consider it worth it to have it on.

That does seem odd, as the overage rate should be 5 dollars per 100MB.